Traffic Lane Marking Line Recognition System for Vehicle

1. A system for recognizing a traffic lane marking line for a vehicle comprising image photographing means for photographing a range including a road surface in a direction of travel of the vehicle; traffic lane marking line recognizing means configured to be capable of recognizing at least a traffic lane marking line in broken line on the road surface in a photographed image photographed by the image photographing means; image compositing means for compositing a plurality of images photographed at different time points by the image photographing means to elongate the traffic lane marking line in the photographed images; brightness detecting means for detecting brightness of the plurality of images photographed by the image photographing means; and brightness correcting means for correcting the brightness, taking one image among the plurality of images as a reference, such that the brightness of the plurality of images are equal to each other; and the image compositing means composites the plurality of images after the brightness has been corrected by the brightness correcting means.

2. The system according to claim 1 , wherein the traffic lane marking line recognizing means is configured to be capable of recognizing the traffic lane marking line through cyclic traffic lane marking line recognition processing, and the one of the images taken as the reference is an image photographed in a current cycle of traffic lane marking line recognition processing.

3. The system according to claim 1 , wherein the brightness detecting means detects the brightness of a predetermined road surface region in the photographed range of the image photographing means.

4. The system according to claim 3 , wherein the image photographing means is configured to be capable of adjusting a shutter speed and iris thereof, and the brightness correcting means corrects the brightness based on at least one of a ratio and a difference of the shutter speed or the iris at photographing time points of the plurality of images.

5. The system according to claim 1 , wherein the image photographing means is configured to be capable of adjusting a shutter speed and iris thereof, the brightness detecting means detects a ratio or difference of brightness in the plurality of images based on at least one of the shutter speed and the iris, and the brightness correcting means corrects the brightness based on at least one of a ratio and a difference of the shutter speed or the iris at photographing time points of the plurality of images.

6. The system according to claim 5 , wherein the image photographing means amplifies and outputs a signal indicative of the photographed image and includes amplification factor adjusting means configured to be capable of adjusting an amplification factor; and the brightness detecting means detects the ratio or the difference of brightness in the plurality of images based on the amplification factor.

7. The system according to claim 1 , wherein the brightness correcting means corrects the brightness such that the brightness of the plurality of images are equal to each other at a same location.

8. The system according to claim 1 , wherein the image compositing means composites the images by selecting one, from among pixels constituting a same area of the plurality of images, that is brighter in the brightness thereof.

9. A vehicle comprising: image photographing means for photographing a range including a road surface in a direction of travel of the vehicle; traffic lane marking line recognizing means configured to be capable of recognizing at least a traffic lane marking line in broken line on the road surface in a photographed image photographed by the image photographing means; image compositing means for compositing a plurality of images photographed at different time points by the image photographing means to elongate the traffic lane marking line in the photographed images; brightness detecting means for detecting brightness of the plurality of images photographed by the image photographing means; and brightness correcting means for correcting the brightness, taking one image among the plurality of images as a reference, such that the brightness of the plurality of images are equal to each other; and the image compositing means composites the plurality of images after the brightness has been corrected by the brightness correcting means.

10. The vehicle according to claim 9 , wherein the traffic lane marking line recognizing means is configured to be capable of recognizing the traffic lane marking line through cyclic traffic lane marking line recognition processing, and the one of the images taken as the reference is an image photographed in a current cycle of traffic lane marking line recognition processing.

11. The vehicle according to claim 9 , wherein the brightness detecting means detects the brightness of a predetermined road surface region in the photographed range of the image photographing means.

12. The vehicle according to claim 11 , wherein the image photographing means is configured to be capable of adjusting a shutter speed and iris thereof, and the brightness correcting means corrects the brightness based on at least one of a ratio and a difference of the shutter speed or the iris at photographing time points of the plurality of images.

13. The vehicle according to claim 9 , wherein the image photographing means is configured to be capable of adjusting a shutter speed and iris thereof, the brightness detecting means detects a ratio or difference of brightness in the plurality of images based on at least one of the shutter speed and the iris, and the brightness correcting means corrects the brightness based on at least one of a ratio and a difference of the shutter speed or the iris at photographing time points of the plurality of images.

14. The vehicle according to claim 13 , wherein the image photographing means amplifies and outputs a signal indicative of the photographed image and includes amplification factor adjusting means configured to be capable of adjusting an amplification factor; and the brightness detecting means detects the ratio or the difference of brightness in the plurality of images based on the amplification factor.

15. The vehicle according to claim 9 , wherein the brightness correcting means corrects the brightness such that the brightness of the plurality of images are equal to each other at a same location.

16. The vehicle according to claim 9 , wherein the image compositing means composites the images by selecting one, from among pixels constituting a same area of the plurality of images, that is brighter in the brightness thereof.

17. A system for recognizing a traffic lane marking line for a vehicle comprising: a camera which photographs a range including a road surface in a direction of travel of the vehicle; a traffic lane marking line recognizing device which recognizes at least a traffic lane marking line in broken line on the road surface in a photographed image photographed by the camera; an image compositing device which composites a plurality of images photographed at different time points by the camera to elongate the traffic lane marking line in the photographed images; a brightness detecting device which detects brightness of the plurality of images photographed by the camera; and a brightness correcting device which corrects the brightness, taking one image among the plurality of images as a reference, such that the brightness of the plurality of images are equal to each other; and the image compositing device composites the plurality of images after the brightness has been corrected by the brightness correcting means.

18. The system according to claim 17 , wherein the traffic lane marking line recognizing device recognizes the traffic lane marking line through cyclic traffic lane marking line recognition processing, and the one of the images taken as the reference is an image photographed in a current cycle of traffic lane marking line recognition processing.

19. The system according to claim 17 , wherein the brightness detecting device detects the brightness of a predetermined road surface region in the photographed range of the camera.

20. The system according to claim 19 , wherein the camera is configured to be capable of adjusting a shutter speed and iris thereof, and the brightness correcting device corrects the brightness based on at least one of a ratio and a difference of the shutter speed or the iris at photographing time points of the plurality of images.